On Fri, Sep 22, 2023 at 12:12:14PM +0800, Ian Kent wrote: > Convert the autofs filesystem to use the mount API. > > The conversion patch was originally written by David Howells. > I have taken that patch and broken it into several patches in an effort > to make the change easier to review. > > Signed-off-by: Ian Kent <raven@xxxxxxxxxx> > --- > fs/autofs/autofs_i.h | 5 +- > fs/autofs/init.c | 9 +- > fs/autofs/inode.c | 247 ++++++++++++++++++++++++------------------- > 3 files changed, 142 insertions(+), 119 deletions(-) > > diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h > index c24d32be7937..244f18cdf23c 100644 > --- a/fs/autofs/autofs_i.h > +++ b/fs/autofs/autofs_i.h > @@ -25,6 +25,8 @@ > #include <linux/completion.h> > #include <linux/file.h> > #include <linux/magic.h> > +#include <linux/fs_context.h> > +#include <linux/fs_parser.h> > > /* This is the range of ioctl() numbers we claim as ours */ > #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY > @@ -205,7 +207,8 @@ static inline void managed_dentry_clear_managed(struct dentry *dentry) > > /* Initializing function */ > > -int autofs_fill_super(struct super_block *, void *, int); > +extern const struct fs_parameter_spec autofs_param_specs[]; > +int autofs_init_fs_context(struct fs_context *fc); > struct autofs_info *autofs_new_ino(struct autofs_sb_info *); > void autofs_clean_ino(struct autofs_info *); > > diff --git a/fs/autofs/init.c b/fs/autofs/init.c > index d3f55e874338..b5e4dfa04ed0 100644 > --- a/fs/autofs/init.c > +++ b/fs/autofs/init.c > @@ -7,16 +7,11 @@ > #include <linux/init.h> > #include "autofs_i.h" > > -static struct dentry *autofs_mount(struct file_system_type *fs_type, > - int flags, const char *dev_name, void *data) > -{ > - return mount_nodev(fs_type, flags, data, autofs_fill_super); > -} > - > struct file_system_type autofs_fs_type = { > .owner = THIS_MODULE, > .name = "autofs", > - .mount = autofs_mount, > + .init_fs_context = autofs_init_fs_context, > + .parameters = autofs_param_specs, > .kill_sb = autofs_kill_sb, > }; > MODULE_ALIAS_FS("autofs"); > diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c > index e2026e063d8c..3f2dfed428f9 100644 > --- a/fs/autofs/inode.c > +++ b/fs/autofs/inode.c > @@ -6,7 +6,6 @@ > > #include <linux/seq_file.h> > #include <linux/pagemap.h> > -#include <linux/parser.h> > > #include "autofs_i.h" > > @@ -111,7 +110,6 @@ static const struct super_operations autofs_sops = { > }; > > enum { > - Opt_err, > Opt_direct, > Opt_fd, > Opt_gid, > @@ -125,35 +123,48 @@ enum { > Opt_uid, > }; > > -static const match_table_t tokens = { > - {Opt_fd, "fd=%u"}, > - {Opt_uid, "uid=%u"}, > - {Opt_gid, "gid=%u"}, > - {Opt_pgrp, "pgrp=%u"}, > - {Opt_minproto, "minproto=%u"}, > - {Opt_maxproto, "maxproto=%u"}, > - {Opt_indirect, "indirect"}, > - {Opt_direct, "direct"}, > - {Opt_offset, "offset"}, > - {Opt_strictexpire, "strictexpire"}, > - {Opt_ignore, "ignore"}, > - {Opt_err, NULL} > +const struct fs_parameter_spec autofs_param_specs[] = { > + fsparam_flag ("direct", Opt_direct), > + fsparam_fd ("fd", Opt_fd), > + fsparam_u32 ("gid", Opt_gid), > + fsparam_flag ("ignore", Opt_ignore), > + fsparam_flag ("indirect", Opt_indirect), > + fsparam_u32 ("maxproto", Opt_maxproto), > + fsparam_u32 ("minproto", Opt_minproto), > + fsparam_flag ("offset", Opt_offset), > + fsparam_u32 ("pgrp", Opt_pgrp), > + fsparam_flag ("strictexpire", Opt_strictexpire), > + fsparam_u32 ("uid", Opt_uid), > + {} > }; > > -static int autofs_parse_fd(struct autofs_sb_info *sbi, int fd) > +struct autofs_fs_context { > + kuid_t uid; > + kgid_t gid; > + int pgrp; > + bool pgrp_set; > +}; > + > +/* > + * Open the fd. We do it here rather than in get_tree so that it's done in the > + * context of the system call that passed the data and not the one that > + * triggered the superblock creation, lest the fd gets reassigned. > + */ > +static int autofs_parse_fd(struct fs_context *fc, int fd) > { > + struct autofs_sb_info *sbi = fc->s_fs_info; > struct file *pipe; > int ret; > > pipe = fget(fd); > if (!pipe) { > - pr_err("could not open pipe file descriptor\n"); > + errorf(fc, "could not open pipe file descriptor"); > return -EBADF; > } > > ret = autofs_check_pipe(pipe); > if (ret < 0) { > - pr_err("Invalid/unusable pipe\n"); > + errorf(fc, "Invalid/unusable pipe"); > fput(pipe); > return -EBADF; > } > @@ -167,58 +178,43 @@ static int autofs_parse_fd(struct autofs_sb_info *sbi, int fd) > return 0; > } > > -static int autofs_parse_param(char *optstr, struct inode *root, > - int *pgrp, bool *pgrp_set, > - struct autofs_sb_info *sbi) > +static int autofs_parse_param(struct fs_context *fc, struct fs_parameter *param) > { > - substring_t args[MAX_OPT_ARGS]; > - int option; > - int pipefd = -1; > + struct autofs_fs_context *ctx = fc->fs_private; > + struct autofs_sb_info *sbi = fc->s_fs_info; > + struct fs_parse_result result; > kuid_t uid; > kgid_t gid; > - int token; > - int ret; > + int opt; > > - token = match_token(optstr, tokens, args); > - switch (token) { > + opt = fs_parse(fc, autofs_param_specs, param, &result); > + if (opt < 0) > + return opt; > + > + switch (opt) { > case Opt_fd: > - if (match_int(args, &pipefd)) > - return 1; > - ret = autofs_parse_fd(sbi, pipefd); > - if (ret) > - return 1; > - break; > + return autofs_parse_fd(fc, result.int_32); > case Opt_uid: > - if (match_int(args, &option)) > - return 1; > - uid = make_kuid(current_user_ns(), option); > + uid = make_kuid(current_user_ns(), result.uint_32); > if (!uid_valid(uid)) > return 1; This and the make_kgid() instance below need to return -EINVAL or use invalfc() to return an error message. I can fix this up though so no need to resend for this.